Parachute Failure, PLEASE HELP

[Goddess Bhavani]

For recovery of moar parts I'd just make the thing into a primitive spaceplane and fly it at high alpha in the upper atmosphere to decelerate. Mini shuttle + runway recovery = fun practise for later spaceplanes.

I'm confident enough currently to progress further and make larger assemblies 'flyable', so as to allow ballistic coasting or skimming the upper atmosphere until its safe to glide down for landing.

[Kryxal]

The funny thing is, I'm seeing considerable lift off the pods for a tourist rocket, a capsule and two inline cockpits. Launching suborbital with a lesser gravity turn, I pick up a fair bit of horizontal speed, then the thing actually GLIDES pretty well at about 25 km altitude while slowing down (angled maybe 15 degrees above the horizon). So long as you have torque to spare, you can generate a LOT of induced drag...

[Sharpy]

Well, early in the game you're bound to generate losses; that's what the initial funds are for. Later on you can begin saving money by recovering increasingly more of your rockets. Still, before the radial parachute, you're bound to put a separator right under the capsule and only recover what was attached to its surface.

Still, before airbrakes there are several tips how to save more than the capsule.

First: Wobble. Don't fly like a torpedo straight down. Get your capsule off the balance position, try to get it as sideways as you can.

Next, powered reentry. Save up some fuel, enter engine first, then somewhere between 30000 and 40000 (when you see your speed is dropping, not increasing!) fire your engine. Possibly at a very low thrust, throttle maybe three notches up. More if you're about to burn up, but orange temperature bars are still within norm, only red should get you worried. (And keep wobbling!)

Make sure a blunt side (either the engine or the "blunt" side of the capsule) is facing forward - the cone of the MK1 capsule makes for a very aerodynamic nose cone.

Before you get the radial parachutes, attach two griders to the capsule and put two more M16 parachutes on them, that way more payload than just the capsule will survive the landing (and they will help with braking too)

Before you get the airbrakes, generally do NOT strive for streamlined shape. You have a plenty of power in SRBs to get you flying, but only limited means of braking. Attach the tourist capsules on two/three/four struts attached radially, so that the contraption has no "lean" side.

(yep, within the 30 parts limit, without struts, I got a test of "test on escape trajectory", using only the BACC boosters; three stages + fourth (payload): 6, 3, 1 BACC. It still got enough of escape velocity that had I attached any science, I'd be able to get "in space Low" science results ( <1mln km from the Sun) - on SRBs alone!

[KSK]

Image album for a fairly basic suborbital flight. Ship consists of a parachute, a capsule, two decouplers and two RT-10s. Doesn't need fins, will do a gravity turn (that is, tip over slowly and automatically without player input) up to a point and slows to chute deploying speeds at about 5,000m.

Javascript is disabled. View full album

Nope - Imgur still broken. Or else I'm doing something wrong.

Edited July 1, 2015 by KSK

[Goddess Bhavani]

I would also add that if there is any indication of abnormal heating, like not being able to dissipate heat and blowing up too early at high altitudes - delete the physics.cfg in the KSP root folder or reinstall KSP to ensure you get the correct 1.0.4 aero and thermal simulation.

A Mk. 1 capsule by itself can conduct ballistic re-entry no problems due to its blunt shape.

It can also conduct orbital re-entry without a heatshield provided there's no additional mass stuck to it. Counter-intuitively, blunt-body re-entry dynamics means an object with a lot of drag heats up slower than one with less drag. Also more drag means starting the deceleration higher up in the atmosphere. More drag + aero-maneuverable re-entry vehicle = omg, one can avoid heating up tremendously by controlling descent rate!

Also I tested and verified a radiator placed on the 'cold' side of a craft dissipates tremendous amount of heat from the parts nearest to itself. Its when the radiator gets into the leading edge and heats up that it acts like it's 'saturated' and heat loss from the ship is drastically reduced. The act of spamming radiators, I suspect is just a gag joke or practical experiment - my micro-shuttles fly with just one and are being tested with ever more aggressive re-entry angles, with no issues so far (partly because they can fly their way out of too-steep re-entry paths and transition to a ballistic coast mode to cool off)

Edited June 30, 2015 by pandoras kitten

[justmeman117]

Wow, that's a lot of replies. I have yet to read them all, but I will. Thank you guys.

I think I figured out on my own how to handle them before people started answering. With that particular rocket, I only had a half second window in which to safely open parachutes, and it took several attempts.

I noticed people were asking about why my rocket's trajectory is so funky. Long story short, I was in career mode (so dont have air brakes), and was just trying to do my first sub orbital flight to get science from space. I strive for a fully reusable space program as is possible, so I also make the attempt to recover as much of a space craft as is possible.

If I remember correctly, this craft was a capsule on top of a single SRB. So, it had no reaction wheels, and no steerable fins. This made aiming for a shallow trajectory very difficult, which is why I was coming in from far higher and steeper than ideal. Most of my SSTOs in the beginning of the program are just big dumb SRB rockets on suborbital launches, so it just sorta goes without much piloting involved.

Anyway, my second iteration, after unlocking more parts, allowed me to put on steerable fins. With 3 capsules, for those pesky tourism missions, fins, and an SRB, I found that even at the steepest reentry angles, the ship was literally able to pull out of a dive (thanks to the new body lift) and climb towards space again. At the apex of 23,000 meters, it was safe to deploy chutes.

Now i've sent a lander to the Mun with a fully reusable launcher (basically a 120 meter tall big dumb liquid rocket), and im still only with bare minimum parts in the tech tree. I think ive got a handle on the new limitations.

Also, I cant figure out how to mark this thread as "answered".

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Pandoras Kitten

This is actually really helpful. I noticed my ship, during launch, wasnt cooling off. It didnt explode, and survived reentry, but It never cooled down. I put them all around the engine bottom (on the twin boar engine, which was overheating). So, what you're saying is, those radiators need to be on the top of the rocket, as far away from the hot engine as possible.

And, what you're saying is, radiators can be used to make space planes more practical? glad to hear it, i was struggling with space planes in 1.0.1

Kryxal

that sounds EXACTLY like the same design I used for my early tourist ship. Mine was actually able to dive in, pull out of the dive, and glide UPWARDS. after pulling out in reentry, it would climb by like, 10km.

Grumman

They are right, the more time you can spend flying sideways in the upper atmosphere, and less time plummeting vertically, the better slowing you'll get. Counter intuitively, this means going faster to make your trajectory longer. I recognized this as the problem as well, but unfortunately couldnt do much with a little controllable SRB.

those few who dared do suborbital flights in real life had an atmosphere almost twice as thick as Kerbins, and fell in low density capsules. They also had stron heat shields. They arent exactly a good example.

Signo

One of the multiple failures was caused by that. I forgot to open the bay with the ground coming up fast. But I was previously aware they cant successfully be opened inside the bay.

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On a side note, I found a pretty cool way of increasing a ship's drag without making it wider.

With large returnable ships, I found there was a problem in which the rocket would touch down, the parachutes cut, it falls over, and explodes. My solution to this was to put all the radial parachutes only on one side. this way, under chute, it falls at an angle, touches the ground, and some of the chutes remain long enough to gently turn it over onto its side.

A side effect of this was a very efficient and stable reentry, despite a harsh speed. The unbalanced weight caused by the parachutes caused the ship to come in at an angle, which greatly increased its drag, and gave it enough body lift for it to remain slowing in the upper atmosphere for a very long time.

It was also difficult to fly without SAS on takeoff, but that's beside the point.

In fact, this solution is not far off from the design of the Apollo space capsule. They were designed to be asymmetrically weighted so that it would reenter at an angle and generate body lift off the heat shield. It had a glide ratio of 1:1 if I remember correctly.

I particularly like this idea, and even though It'll make launches a bit more difficult (at least till I get SAS probes), I think the natural tendency to reenter safely is well worth making my large ships unbalanced.

Edited July 1, 2015 by justmeman117

[AlexinTokyo]

You can change 'Unanswered' to 'Answered' by editing the OP in advanced mode.

Details here: http://forum.kerbalspaceprogram.com/threads/85063-How-to-change-Unanswered-to-Answered

[justmeman117]

thanks

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If you guys want, we could continue discussing optimum ways to reenter. I think a lot of people would find it helpful.